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Full text of "Treatise On Applied Analytical Chemistry(Vol-1)"

CHAPTER VIII

MINERAL   OILS
AND PRODUCTS DERIVED FROM THEM

Crude -petroleum yields various industrial products which may be grouped
in the following classes :

1.  Light oils (gasoline and naphtha), b.pt. below 150° C.

2.  Lamp oil or kerosene, principally the fractions boiling between 150°
and 310°.                                                   i • i

3.  Medium oils (gas oils), intermediate to lamp oil and the heavy oils.

4.  Heavy oils, which include the fractions distilHng above 300-310°
and treated to render them suitable as lubricants.

5.  Residuum, which consists of the residue left after distillation of the
light and medium oils and sometimes also of part of the heavy oils, without
further treatment.

6.  Vaseline, composed of hydrocarbons semi-solid at the ordinary tem-
perature.

7.  Solid paraffin or paraffin wax, formed of solid hydrocarbons.
Products analogous to these are obtained by distillation of bituminous

shales and are termed shale oils ; these also yield light oils (shale spirit),
'burning oils, heavy oils, and a considerable quantity of solid paraffin.

Similar to the last is ceresine, obtained by refining ozokerite or earth
wax. A product of similar appearance to ozokerite is montan wax.

These products are treated in the following articles, together with lubri-
cants, now largely used industrially and mostly having a basis of mineral oil.

In sampling these products, reference may be made to the directions
given for tar.

CRUDE PETROLEUM

This is usually a brown or blackish liquid, but sometimes reddish or
yellow, with a characteristic bituminous odour; it is often turbid owing
to the presence of suspended water and solid substances.

The tests to be made are partly physical and partly chemical.

1. Physical Examination

1. Determination of the Specific Gravity.—The hydrometer or the
Westphal balance is used, or, if the amount of substance available is small

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